[breaking-change]
1. The internal layout for traits has changed from (vtable, data) to (data, vtable). If you were relying on this in unsafe transmutes, you might get some very weird and apparently unrelated errors. You should not be doing this! Prefer not to do this at all, but if you must, you should use raw::TraitObject rather than hardcoding rustc's internal representation into your code.
2. The minimal type of reference-to-vec-literals (e.g., `&[1, 2, 3]`) is now a fixed size vec (e.g., `&[int, ..3]`) where it used to be an unsized vec (e.g., `&[int]`). If you want the unszied type, you must explicitly give the type (e.g., `let x: &[_] = &[1, 2, 3]`). Note in particular where multiple blocks must have the same type (e.g., if and else clauses, vec elements), the compiler will not coerce to the unsized type without a hint. E.g., `[&[1], &[1, 2]]` used to be a valid expression of type '[&[int]]'. It no longer type checks since the first element now has type `&[int, ..1]` and the second has type &[int, ..2]` which are incompatible.
3. The type of blocks (including functions) must be coercible to the expected type (used to be a subtype). Mostly this makes things more flexible and not less (in particular, in the case of coercing function bodies to the return type). However, in some rare cases, this is less flexible. TBH, I'm not exactly sure of the exact effects. I think the change causes us to resolve inferred type variables slightly earlier which might make us slightly more restrictive. Possibly it only affects blocks with unreachable code. E.g., `if ... { fail!(); "Hello" }` used to type check, it no longer does. The fix is to add a semicolon after the string.
declared with the same name in the same scope.
This breaks several common patterns. First are unused imports:
use foo::bar;
use baz::bar;
Change this code to the following:
use baz::bar;
Second, this patch breaks globs that import names that are shadowed by
subsequent imports. For example:
use foo::*; // including `bar`
use baz::bar;
Change this code to remove the glob:
use foo::{boo, quux};
use baz::bar;
Or qualify all uses of `bar`:
use foo::{boo, quux};
use baz;
... baz::bar ...
Finally, this patch breaks code that, at top level, explicitly imports
`std` and doesn't disable the prelude.
extern crate std;
Because the prelude imports `std` implicitly, there is no need to
explicitly import it; just remove such directives.
The old behavior can be opted into via the `import_shadowing` feature
gate. Use of this feature gate is discouraged.
This implements RFC #116.
Closes#16464.
[breaking-change]
These are like the existing bsearch methods but if the search fails,
it returns the next insertion point.
The new `binary_search` returns a `BinarySearchResult` that is either
`Found` or `NotFound`. For convenience, the `found` and `not_found`
methods convert to `Option`, ala `Result`.
Deprecate bsearch and bsearch_elem.
This required some contortions because importing both raw::Slice
and slice::Slice makes rustc crash.
Since `Slice` is in the prelude, this renaming is unlikely to
casue breakage.
[breaking-change]
ImmutableVector -> ImmutableSlice
ImmutableEqVector -> ImmutableEqSlice
ImmutableOrdVector -> ImmutableOrdSlice
MutableVector -> MutableSlice
MutableVectorAllocating -> MutableSliceAllocating
MutableCloneableVector -> MutableCloneableSlice
MutableOrdVector -> MutableOrdSlice
These are all in the prelude so most code will not break.
[breaking-change]
- Moved examples for permutations and next into trait definition as
comments on pull request #16244.
- Fixed (hopefully) issue with erronious commit of changes to src/llvm.
- API doc/example for next() in Permutations
- API doc/example for permutations() in ImmutableCloneableVector
- Moved examples for permutations and next into trait definition as
comments on pull request #16244.
- Fix erroneus inclusion of src/llvm in older commit.
This does a few things:
- remove references to ~[] and the OwnedVector trait, which are both
obsolete
- correct the docs to say that this is the slice module, not the vec
module
- add a sentence pointing out that vectors are distinct from Vec
- remove documentation on Vec.
closes#15459
Implement for Vec, DList, RingBuf. Add MutableSeq to the prelude.
Since the collections traits are in the prelude most consumers of
these methods will continue to work without change.
[breaking-change]
floating point numbers for real.
This will break code that looks like:
let mut x = 0;
while ... {
x += 1;
}
println!("{}", x);
Change that code to:
let mut x = 0i;
while ... {
x += 1;
}
println!("{}", x);
Closes#15201.
[breaking-change]
This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
Replace its usage with byte string literals, except in `bytes!()` tests.
Also add a new snapshot, to be able to use the new b"foo" syntax.
The src/etc/2014-06-rewrite-bytes-macros.py script automatically
rewrites `bytes!()` invocations into byte string literals.
Pass it filenames as arguments to generate a diff that you can inspect,
or `--apply` followed by filenames to apply the changes in place.
Diffs can be piped into `tip` or `pygmentize -l diff` for coloring.
The following features have been removed
* box [a, b, c]
* ~[a, b, c]
* box [a, ..N]
* ~[a, ..N]
* ~[T] (as a type)
* deprecated_owned_vector lint
All users of ~[T] should move to using Vec<T> instead.
This commit moves Mutable, Map, MutableMap, Set, and MutableSet from
`core::collections` to the `collections` crate at the top-level. Additionally,
this removes the `deque` module and moves the `Deque` trait to only being
available at the top-level of the collections crate.
All functionality continues to be reexported through `std::collections`.
[breaking-change]
This commit carries out the request from issue #14678:
> The method `Iterator::len()` is surprising, as all the other uses of
> `len()` do not consume the value. `len()` would make more sense to be
> called `count()`, but that would collide with the current
> `Iterator::count(|T| -> bool) -> unit` method. That method, however, is
> a bit redundant, and can be easily replaced with
> `iter.filter(|x| x < 5).count()`.
> After this change, we could then define the `len()` method
> on `iter::ExactSize`.
Closes#14678.
[breaking-change]
As with the previous commit with `librand`, this commit shuffles around some
`collections` code. The new state of the world is similar to that of librand:
* The libcollections crate now only depends on libcore and liballoc.
* The standard library has a new module, `std::collections`. All functionality
of libcollections is reexported through this module.
I would like to stress that this change is purely cosmetic. There are very few
alterations to these primitives.
There are a number of notable points about the new organization:
* std::{str, slice, string, vec} all moved to libcollections. There is no reason
that these primitives shouldn't be necessarily usable in a freestanding
context that has allocation. These are all reexported in their usual places in
the standard library.
* The `hashmap`, and transitively the `lru_cache`, modules no longer reside in
`libcollections`, but rather in libstd. The reason for this is because the
`HashMap::new` contructor requires access to the OSRng for initially seeding
the hash map. Beyond this requirement, there is no reason that the hashmap
could not move to libcollections.
I do, however, have a plan to move the hash map to the collections module. The
`HashMap::new` function could be altered to require that the `H` hasher
parameter ascribe to the `Default` trait, allowing the entire `hashmap` module
to live in libcollections. The key idea would be that the default hasher would
be different in libstd. Something along the lines of:
// src/libstd/collections/mod.rs
pub type HashMap<K, V, H = RandomizedSipHasher> =
core_collections::HashMap<K, V, H>;
This is not possible today because you cannot invoke static methods through
type aliases. If we modified the compiler, however, to allow invocation of
static methods through type aliases, then this type definition would
essentially be switching the default hasher from `SipHasher` in libcollections
to a libstd-defined `RandomizedSipHasher` type. This type's `Default`
implementation would randomly seed the `SipHasher` instance, and otherwise
perform the same as `SipHasher`.
This future state doesn't seem incredibly far off, but until that time comes,
the hashmap module will live in libstd to not compromise on functionality.
* In preparation for the hashmap moving to libcollections, the `hash` module has
moved from libstd to libcollections. A previously snapshotted commit enables a
distinct `Writer` trait to live in the `hash` module which `Hash`
implementations are now parameterized over.
Due to using a custom trait, the `SipHasher` implementation has lost its
specialized methods for writing integers. These can be re-added
backwards-compatibly in the future via default methods if necessary, but the
FNV hashing should satisfy much of the need for speedier hashing.
A list of breaking changes:
* HashMap::{get, get_mut} no longer fails with the key formatted into the error
message with `{:?}`, instead, a generic message is printed. With backtraces,
it should still be not-too-hard to track down errors.
* The HashMap, HashSet, and LruCache types are now available through
std::collections instead of the collections crate.
* Manual implementations of hash should be parameterized over `hash::Writer`
instead of just `Writer`.
[breaking-change]
